Generally speaking, the insulated glass assembly art is a well developed art as is the spacer art. The use of various plastics for fabricating the spacers in such insulated glass assemblies has been the subject of many patents, typical of which is U.S. Pat. No. 4,658,553, issued Apr. 21, 1987 to Shinagawa. The reference discloses the use of a resinous material for spacing glass sheets in a refrigerated display case. Although this reference discloses the use of a resinous material for use in the fabrication of the spacer, from a structural point of view the surface area contact of the spacer on the glass substrates is at a maximum and additionally the front portion of the spacer in contact with the internal atmosphere of the assembly extends between and contacts each of the substrates. Further still, the spacer in the Shinagawa reference provides a large internal volume within the spacer. Based on these elements, it would appear to be susceptible to energy transfer from one substrate to the other, based on the structure of this spacer.
Eriksson et al., in U.S. Pat. No. 4,719,728, issued Jan. 19, 1988, disclose a collapsible spacer member. Collapsibility of the spacer is achieved by the use of notches in the body at the corners and mediaily of two sides. The two sides contact each of the substrates. Although this arrangement is useful to some extent, it would appear to be quite limited in terms of the ability of the same to function effectively from an energy conservation point of view. It would appear that energy transfer may be pronounced at the areas where the notches are since the same reduce the thickness of the body of the spacer.
U.S. Pat. No. 4,335,166, issued Jun. 15, 1982, to Lizardo et al., teaches a method of manufacturing a multi-pane insulating glass unit. The spacer employed in this arrangement is indicated to comprise a roll formed plastic spacer. Similar to the Shinagawa reference discussed hereinabove, this reference additionally provides a spacer body having a relatively large internal volume as well as a support member contacting the internal atmosphere of the assembly which extends between and contacts each of the panes. The support member may act as a thermal bridge from one substrate to the other similar to the difficulty previously encountered with metal spacers although to a somewhat more limited degree due to the incorporation of plastics in the spacer.
It is evident that there is a need in the spacer and insulated glass assembly art for an improved spacer which substantially reduces thermal transfer between the substrates and subsequently which reduces heat loss at the perimeter of the insulated assembly. The present invention is directed to providing a solution to the problem of energy efficiency in the insulated glass assembly art.